A GCN4 protein recognition element is not sufficient for GCN4-dependent regulation of transcription in the ARO7 promoter of Saccharomyces cerevisiae.
The gene ARO7 encodes the monofunctional enzyme chorismate mutase, a branch point enzyme in the aromatic amino acid biosynthetic pathway in Saccharomyces cerevisiae. We investigated the transcription of the ARO7 gene. Three 5' ends at positions -36, -56 and -73 and the 3' end of the transcripts 146 bp downstream of the translational stop codon were mapped. As in the promoters of other aromatic amino acid biosynthetic genes, a recognition element for the GCN4 transcriptional activator of amino acid biosynthesis is located 425 base pairs (bp) upstream of the first transcriptional start point. This element binds GCN4 specifically in vitro. Northern analysis and determination of the specific enzyme activity reveals however, that the element is not sufficient to mediate transcriptional regulation by GCN4 in vivo. We thus suggest that in addition to a consensus sequence capable of binding the GCN4 protein other factors like, for example, chromatin structure, determine whether a recognition site for a transcription factor functions as an upstream activation sequence.
Schmidheini
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T
Mikrobiologisches Institut, Eidgenössische Technische Hochschule, ETH-Zentrum, Zürich, Switzerland.
Mösch
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HU
Graf
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Braus
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GH
D015152:Blotting, Northern; D015139:Blotting, Southern; D002826:Chorismate Mutase / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D015825:Chromosomes, Fungal; D016384:Consensus Sequence; D004268:DNA-Binding Proteins; D003850:Deoxyribonuclease I / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D011401:Promoter Regions, Genetic; D011494:Protein Kinases; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011494:Protein Kinases; D003850:Deoxyribonuclease I; D002826:Chorismate Mutase